Workpiece treating apparatus

ABSTRACT

A workpiece treating apparatus includes an endless conveyor for moving the workpieces therein to expose them to treating means which projects treating media against the workpieces. The conveyor is made of individual slats extending perpendicular to its direction of movement and each slat has grooves to enhance the ricocheting action of the treating media.

United States Patent 1191 Long, III [451 May 29, 1973 [54] WORKPIECE TREATINGAPPARATUS [56] References Cited [75] Inventor: William W. Long llL' Hagerstown, UNITED STATES PATENTS 1,457,284 5/1923 [73] Assignee: The Ca'rborundumj Company, ,7 6/1971 Niagara Falls N Y 2,574,867 1 1/1951 2,724,929 11/1955 [22] Filed: May 4, 1971 2,716,310 8/1955 1,882,443 10/1932 1 pp 140,199 3,390,487 7/1968 7 Related Appucatiou Data 1 Primary Examiner-Donald G. Kelly [63] Continuation-impart of Set. No. 859,991, Sept. 22, Atwmey-R9bert Wlater and David Dougherty 1969, abandoned.

[57] ABSTRACT 52 vs. 01. ..51/9, 51/13, 51/14 A workpiece treating apparatus includes an endless Illl- B246 B 1 conveyor for moving the workpieces therein to expose 'Field .of Search ..5l/8, 9, them to treating means which projects treating media against the workpieces. The conveyor is made of individual slats extending perpendicular to its direction of movement and each slat has grooves to enhance the ricocheting action of the treating media.

9 Claims, 6 Drawing Figures WORKPIECE TREATING APPARATUS CROSS-REFERENCE TO RELATED APPLICATION This application is a continuation-in-part of copending application Ser. No. 859,991, filed Sept. 22, 1969, now abandoned.

BACKGROUND OF INVENTION Various treating devices exist such as abrasive blast cleaning devices wherein the workpieces are inserted in an endless trough-like slatted conveyor and tumbled so that all portions of the workpieces are exposed to the abrasive blast particles which are projected from the blast wheels. A certain amount of ricocheting action of the projected particles takes place with such arrangements. Examples of such devices are in U.S. Pat. No.

2,716,3 10 which relates to a batch cleaning device and in U.S. Pat. No. 2,574,867 which relates to a continuous cleaning device. The essential difference between both devices is that in the batch cleaning device the endless conveyor is mounted in a housing having a door so that a batch of workpieces can be inserted and subsequently removed therefrom. In the continuous cleaning device the endless conveyor communicates with a feed drum or chamber and a discharge drum so that workpieces can continuously be fed into and discharged from the endless conveyor.

SUMMARY OF INVENTION An object of this invention is to provide a slat conveyor arrangement which maximizes the ricocheting action of the projected particles with minimum energy loss due to rebound.

A further object of this invention is to provide such an arrangement which can be utilized in either a batch treating or a continuous treating apparatus.

In accordance with this invention the slats of the conveyor are arranged in the usual manner; namely, perpendicular to their direction of movement. Each slat contains grooves which are so designed as to enhance the ricocheting action of the particles. In an advantageous form of this invention the grooves are arcuate in cross-section such as being the segment of a circle. The grooves may be disposed at an angle to the direction of the abrasive blast wheel such as approximately 55.

THE DRAWINGS FIG. 1 shows a batch cleaning apparatus in crosssectional elevation view incorporating the slat conveyor of this invention;

FIG. 2 is a side view of a portion of the slat conveyor shown in FIG. 1;

FIG. 3 is a plan view of the slat conveyor shown in FIG. 2;

FIG. 4 is a cross-sectional view taken through FIG. 3 along the line 44;

FIG. 5 is a side elevation view in section of another form of this invention; and

FIG. 6 is a top plan view of the embodiment of the invention shown in FIG. 5.

DETAILED DESCRIPTION FIG. 1 shows a batch cleaning apparatus 10 which includes a housing 12 having an endless slatted conveyor 14 therein. The endless conveyor is driven by sprockets l6, 18, 20 in a manner described in greater detail in U.S. Pat. No. 2,716,310. Since details of the drive and other details of the housing are well known in the art, as described in the aforesaid patent, a description hereof will be omitted except where such description will facilitate an understanding of this invention. I-Io'using 10 includes a retractable door 22 to permit workpieces to be inserted in the trough formed by the endless conveyor 14 while one or more treating devices such as abrasive blast wheel 24 is disposed at the top of housing 10 to project particles against the workpieces.

Although a batch cleaning apparatus is illustrated in FIG. 1 it is to be understood that the endless conveyor of this invention can also be incorporated in continuous cleaning devices such as described in U.S. Pat. Nos. 2,574,864; 2,724,929 and 2,441,578. Such continuous cleaning devices generally include a treating chamber similar to the treating chamber 26 of FIG. I. However, instead of having the chamber mounted within a housing and accessible through a door, the treating chamber communicates with a feed chamber and a discharge chamber so that workpieces can be supplied to and from the treating chamber in a continuous manner.

FIGS. 2-4 show the details of a portion of a single slat in accordance with this invention. As indicated therein the slat 28 includes an offset flange 30 which is driven in any suitable manner and the cleat 32 which supports and tumbles the workpieces. The surface of cleat 32 exposed to the abrasive blast particles includes ricochet enhancing grooves 34. A convenient manner of forming cleat 32 with grooves 34 would be to secure together a plurality of pipe segments.

As best shown in FIG. 4 grooves 34 are of arcuate cross-section being for example segments of circles. Additionally, as illustrated in FIG. 3 grooves 34 are inclined with respect to the direction of movement of the conveyor which is indicated by the arrow A by an angle of approximately 55. In other words the grooves are at an angle C of about 35 with respect to the longitudinal center line B of each cleat.

With the particular shaped grooves illustrated in FIGS. 2-4 and described above, a maximum ricocheting action of the abrasive particles is obtained with minimum energy loss due to rebound. In this regard the curved sides of the grooves act as rebounding surfaces and the sliding action of the rebound particles occurs on the curved surfaces to reduce the kinetic energy transfer of abrasive particles to the rebounding surfaces.

As shown in FIGS. 17-6 the slat conveyor incorporating the novel grooved slats is illustrated as being in the form of a flat endless conveyor 36. As with the embodiment of the invention best illustrated in FIG. 4 a plurality of grooves 38 are provided in the supporting face of the conveyor with the grooves being of arcuate form as for example obtained by cutting pipe sections in half. The grooves are disposed perpendicular to the direction of movement of conveyor 36. Conveyor 36 is driven in any suitable manner such as by gears 40 for each end thereof. Additionally, a feed chute 42 is provided so that the parts 44 being treated may slide through chute 42 and be disposed on the groove support surface 38. In accordance with this invention one or more centrifugal blast wheels 46 are provided arranged at an angle to the grooves. This angle D is for example about 55 which is the same angle indicated in FIG. 3 by the arrow A. Since the blast wheel is at an angle to the arcuate grooves there is assurance of a random type impact of the blast particles against the various portions of different grooves which results in an effective ricocheting action to maximize the cleaning ability of this arrangement.

A further advantage with this arrangement is that the grooves 38 serve to collect spent abrasive particles as indicated in FIG. by the grooves 38a. As the conveyor changes its direction when riding over gear 44) the spent abrasive is collected in hopper 48. Guide rails 56 are also provided along the sides of the conveyor to confine the parts 44 on the conveyor. Additionally, a discharge chute S2 is provided to discharge the cleaned parts from the exit end of the conveyor.

An arrangement has thereby been provided which results in maximum ricocheting action with minimum velocity loss by having the blast wheel at an angle to the conveyor grooves and by having the grooves disposed perpendicular to the direction of travel of the conveyor.

The enhanced ricocheting action is also achieved in the arrangement shown in FIG. 1 in that the blast wheel 24 is disposed straight downward so that the grooves 34 are arranged at the advantageous 55 angle with respect to the blast wheel.

What is claimed is:

1. In a workpiece treating apparatus including a treating chamber having an endless conveyor therein, means for driving said conveyor for moving the workpieces therein, a centrifugal throwing wheel having an axis of rotation disposed adjacent said conveyor for projecting abrasive particles toward said conveyor and against the workpieces in a direction substantially normal to the axis of rotation of said centrifugal throwing wheel, said conveyor being made of individual slats extending perpendicular to the direction of movement of 35 said conveyor, and each of said slats having ricochet enhancing grooves in its surface disposed toward said centrifugal throwing wheel, said grooves being at an angle with respect to the direction of projection of abrasive pa ticles.

2. An apparatus as set forth in claim 1 wherein said grooves are arcuate in cross-section.

3. An apparatus as set forth in claim 2 wherein the arcuate cross-section of said grooves is the segment of a circle.

4., An apparatus as set forth in claim 3 wherein said angle is approximately 55.

5. An apparatus as set forth in claim 3 wherein said treating means includes an abrasive particle projecting machine, said apparatus being a continuous cleaning apparatus, a feed chamber communicating with said treating chamber, and a discharge charnber communieating with said treating chamber.

6. An apparatus as set forth in claim 3 wherein said treating means includes an abrasive particle projecting machine, said appa atus being a batch cleaning apparatus, a housing enclosing said treating chamber, said conveyor being trough-like, and a door in said housing exposed to said treating chamber.

7. An apparatus as set forth. in claim 3 wherein said endless conveyor is a flat conveyor, said grooves being perpendicular to the direction of movement of said conveyor, and said treating means being an abrasive blast machine mounted at said angle to said grooves.

8. An apparatus as set forth in claim 7 wherein said blast machine is a centn'fugal throwing wheel.

9. An apparatus as set forth in claim 3 wherein the worxpieces are continuously fed onto and discharged from said endless conveyor. 

1. In a workpiece treating apparatus including a treating chamber having an endless conveyor therein, means for driving said conveyor for moving the workpieces therein, a centrifugal throwing wheel having an axis of rotation disposed adjacent said conveyor for projecting abrasive particles toward said conveyor and against the workpieces in a direction substantially normal to the axis of rotation of said centrifugal throwing wheel, said conveyor being made of individual slats extending perpendicular to the direction of movement of said conveyor, and each of said slats having ricochet enhancing grooves in its surface disposed toward said centrifugal throwing wheel, said grooves being at an angle with respect to the direction of projection of abrasive particles.
 2. An apparatus as set forth in claim 1 wherein said grooves are arcuate in cross-section.
 3. An apparatus as set forth in claim 2 wherein the arcuate cross-section of said grooves is the segment of a circle.
 4. An apparatus as set forth in claim 3 wherein said angle is approximately 55*.
 5. An apparatus as set forth in claim 3 wherein said treating means includes an abrasive particle projecting machine, said apparatus being a continuous cleaning apparatus, a feed chamber communicating with said treating chamber, and a discharge chamber communicating with said treating chamber.
 6. An apparatus as set forth in claim 3 wherein said treating means includes an abrasive particle projecting machine, said apparatus being a batch cleaning apparatus, a housing enclosing said treating chamber, said conveyor being trough-like, and a door in said housing exposed to said treating chamber.
 7. An apparatus as set forth in claim 3 wherein said endless conveyor is a flat conveyor, said grooves being perpendicular to the direction of movement of said conveyor, and said treating means being an abrasive blast machine mounted at said angle to said grooves.
 8. An apparatus as set forth in claim 7 wherein said blast machine is a centrifugal throwing wheel.
 9. An apparatus as set forth in claim 3 wherein the workpieces are continuously fed onto and discharged from said endless conveyor. 